Communities II Flashcards
What species of birds experiences the most loss?
parrots
How much is a pair of Hyacinth Macaw birds worth?
- $30,000
- found in Bolivia
why are macaws so heavily sought after in Bolivia?
the average family income is $900-$1000 while one pair of Macaws is worth $30,000.
where is the highest diversity of species located and why?
the Andes mountains because as you go higher, the habitat continually changes
what are latitudinal gradients in biodiversity?
as you move away from the equator, the species density declines.
Where do you find more variation in bill size in birds?
tropical zones as opposed to temperate zones.
What is the overall difference between tropical birds and temperate birds?
- tropical birds are more specialized because they have a smaller niche than temperate birds.
- tropical birds are more evolutionarily driven by inter-species interactions while temperate birds are more evolutionarily driven by cold or harsh temperature conditions.
how many species of birds are there on earth?
10,000
What is one theory for why there is more bird diversity in the tropics?
- plant diversity is higher in the tropics therefore there is more available niches
True or False: Communities generally stay the same over time.
False, communities can change dramatically over the course of even one year.
define competitive exclusion.
no two species are able to occupy the same niche
- ex: hummingbirds
Define Interference competition.
Overt aggressive displacement of another species.
- sometimes large males push out even smaller females of the same species during the NON-breeding season
Define exploitative competition and give an example.
when one species reduces the resources available to another species (food, habitats)
- ex: when removing great tits from a habitat, the population of blue tits shot up.
Define Character Displacement.
birds being displaced into different (more specialized) niches due to competition, resulting in physical changes.
Define Ecological Displacement.
birds being displaced into different (more specialized) niches due to competition, resulting in habitat changes.
